KR20200134497A - A parking space pose estimation method and apparatus - Google Patents

Abstract

Disclosed are a method and a device for estimating a parking space pose. The method for estimating a parking space pose includes the steps of: (a) acquiring at least one of vehicle speed and steering information; (b) estimating a vehicle pose in a parking space coordinate system according to a vehicle motion using at least one of the vehicle speed and steering information; and (c) estimating a parking space pose in the vehicle coordinate system using the estimated vehicle pose based on a pose transformation matrix.

Description

A parking space pose estimation method and apparatus therefor

The present invention relates to a method and apparatus for estimating a parking space pose by using the pose estimation of a parking vehicle.

In the conventional parking assistance system (SPAS), an obstacle is detected using sensors such as ultrasonic waves that have a limited sensing distance and direction of a parked vehicle to find a part of an empty space where parking is possible, and if the driver wants to park in that empty space, the empty space This is a method of controlling the steering of the vehicle by creating a parking path composed of a combination of an arc and a straight line so that the vehicle can enter the vehicle and by directly obtaining steering from the arc and straight parking path.

Such a conventional parking assistance system consists of a combination of arcs and straight lines so that the driver can advance the vehicle to move the position when the vehicle cannot fully enter the parking space, and the vehicle can enter the space from the moved position again. It creates a parking path to control the steering of the vehicle by directly obtaining steering from the arc and straight parking paths.

In other words, when the vehicle enters the parking space by creating a path consisting of a combination of arcs and straight lines to the location determined at the entrance to the empty space, the vehicle continues to detect obstacles in the parking lot and controls only the steering angle to secure a gap with surrounding obstacles. It serves to assist the driver to make it easier. That is, when the driver determines that parking is complete and stops the parking assistance, the runner assistance is terminated.

The conventional parking assistance methods using an image obtain pose information of several landmarks whose position or pose is known in advance by an image sensor, and extract the pose of the image sensor, which is a common criterion for all information, using a trigonometric method. to be.

Therefore, the conventional method has a problem in that the pose of the image sensor photographing the landmark cannot be obtained if the pose of the landmark is not known in advance.

(01) Japanese Patent Publication No. 4052198 (2007.12.14.)

The present invention is to provide a method and apparatus for estimating a parking space pose by using the pose estimation of a parking vehicle.

In addition, the present invention is to provide a parking space pose estimation method and apparatus capable of estimating a pose of a parking space based on a pose of a vehicle even when an image sensor is not normally used due to external conditions.

According to an aspect of the present invention, a method of estimating a parking space pose using pose estimation of a parked vehicle is provided.

According to an embodiment of the present invention, there is provided a method for estimating a parking space pose, the method comprising: (a) acquiring at least one of vehicle speed and steering information; (b) estimating a vehicle pose in a parking space coordinate system according to a vehicle motion using at least one of the vehicle speed and steering information; And (c) estimating a parking space pose in a vehicle coordinate system using the estimated vehicle pose based on a pose transformation matrix.

In step (b), the vehicle pose on the parking space coordinate system during parking using the steering information is predicted by the following equation,

는 주차공간 좌표계상의 현재 차량의 포즈를 나타내고,

는 조향 정보를 나타낸다.here,

Represents the current vehicle pose in the parking space coordinate system,

Indicates steering information.

The vehicle pose on the parking space coordinate system is converted into a parking space pose on the vehicle coordinate system by the following equation,

는 포즈변환 메트릭스를 나타내며,

는 주차공간 좌표계상의 차량의 헤딩각을 나타내고,

는 주차공간 좌표계상의 차량 포즈 예측치를 나타낸다. here,

Represents the pose transformation matrix,

Represents the heading angle of the vehicle in the parking space coordinate system,

Represents the predicted vehicle pose in the parking space coordinate system.

The parking space pose is a pose for a parking completion point, which is the center of the rear wheel axis of the parked vehicle when parking is completed for the parking space.

According to another aspect of the present invention, an apparatus for estimating a parking space pose using pose estimation of a parked vehicle is provided.

According to an embodiment of the present invention, there is provided a pose estimation apparatus for estimating a parking space pose in connection with a vehicle, comprising: an acquisition unit that obtains at least one of speed and steering information of a vehicle; A vehicle pose estimating unit for estimating a vehicle pose on a parking space coordinate system according to a vehicle motion using at least one of the vehicle speed and steering information; And a parking space pose estimating unit for estimating a parking space pose in a vehicle coordinate system using the estimated vehicle pose based on a pose transformation matrix.

According to another embodiment of the present invention, a sensor for sensing at least one of speed and steering information of a vehicle; And estimating a vehicle pose in a parking space coordinate system according to vehicle motion using at least one of the vehicle speed and steering information, and estimating a parking space pose in the vehicle coordinate system using the estimated vehicle pose based on a pose transformation matrix. A vehicle including a pose estimation unit may be provided.

By providing a method and apparatus for estimating a parking space pose according to an embodiment of the present invention, the pose of a parking space may be estimated using the pose estimation of a parking vehicle.

In addition, the present invention has the advantage of estimating the pose of the parking space based on the pose of the vehicle even when the image sensor is not normally used due to external conditions.

1 is a flow chart showing a parking space pose estimation method according to an embodiment of the present invention.
2 is a view illustrating each coordinate system according to an embodiment of the present invention.
3 is a block diagram schematically showing the internal configuration of a pose estimation apparatus according to an embodiment of the present invention.

Singular expressions used in the present specification include plural expressions unless the context clearly indicates otherwise. In the present specification, terms such as “consisting of” or “comprising” should not be construed as necessarily including all of the various elements or various steps described in the specification, and some of the elements or some steps It may not be included, or it should be interpreted that it may further include additional elements or steps. In addition, terms such as "... unit" and "module" described in the specification mean units that process at least one function or operation, which may be implemented as hardware or software, or as a combination of hardware and software. .

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a flowchart illustrating a method of estimating a parking space pose according to an embodiment of the present invention, and FIG. 2 is a view illustrating each coordinate system according to an embodiment of the present invention. In step 110, the pose estimating apparatus 100 obtains at least one of speed and steering information from the interlocked vehicle.

The pose estimation apparatus 100 according to an embodiment of the present invention may be interlocked with an electronic control unit (ECU) of a vehicle or may be a part of an electronic control unit. Accordingly, the pose estimating apparatus 100 may acquire various sensing values from various sensors mounted in the vehicle through the electronic control unit (ECU).

The pose estimation apparatus 100 according to an embodiment of the present invention assumes that the image signal of the image sensor mounted on the vehicle cannot be used normally, and based on at least one of the vehicle speed and steering information, the vehicle in the parking space coordinate system After estimating the pose, a method of estimating the parking space pose based on this will be described.

Accordingly, it should be understood that the pose estimation apparatus 100 according to an embodiment of the present invention cannot use the image signal from the image sensor of the vehicle, even if there is no separate description below.

In step 115, the pose estimation apparatus 100 estimates a parked vehicle pose on the parking space coordinate system using at least one of the vehicle speed and steering information.

First, in order to facilitate understanding and explanation, a vehicle coordinate system and a parking space coordinate system will be first described with reference to FIG. 2.

The parking space pose represents a pose for a parking completion point where the center of the rear wheel axis (CRA: Center of Rear Axle, hereinafter referred to as CRA) of the parked vehicle is located when the parked vehicle has completed parking for the parking space.

For convenience of understanding and explanation, this will be described in more detail with reference to FIG. 2.

로 표시하기로 한다. 여기서, 목적물은 차량일수도 있으며, 주차 공간일 수도 있다.The pose of the object in an arbitrary coordinate system

I will mark it as. Here, the target object may be a vehicle or a parking space.

)으로 나타낼 수 있다. When the object exists on the {xy} plane, the pose of the object is the position (x,y) in the coordinate system of the specified point of the object and the rotation angle that the object makes with the {z} axis (

) Can be represented.

The present invention relates to the estimation of a parking vehicle pose, and the object may be a vehicle or a parking space. Accordingly, a vehicle coordinate system and a parking space coordinate system may exist as a coordinate system.

평면에 주차공간이 존재하고,

평면에 주차 차량이 존재하는 것을 가정하여 설명하기로 한다. In an embodiment of the present invention, in order to facilitate understanding and explanation,

There is a parking space on the plane,

The description will be made on the assumption that there is a parking vehicle on the plane.

로 표시하며, 차량좌표계는

로 표시하기로 한다.In an embodiment of the present invention, the parking space coordinate system

And the vehicle coordinate system is

I will mark it as.

In an embodiment of the present invention, the parking space coordinate system is defined as a coordinate system fixed to the parking space with the parking completion point as a specific point as the origin.

In addition, the vehicle coordinate system is defined as a coordinate system fixed to the parked vehicle with the parking completion point (CRA) of the vehicle as the origin.

로 나타내기로 한다. When a parking space is specified using an image sensor of a parked vehicle, a parking completion point of the parking space may be designated as a specific point, and a pose for the parking completion point may be designated as a parking space pose. The parking completion point of the parking space

It will be represented by.

로 표시한다. The parking space pose is the pose of the parking completion point set in the parking space.

Denoted by

에 해당하는 주차공간 좌표계의 원점이다.2, the parking completion point is in the parking space coordinate system.

It is the origin of the parking space coordinate system corresponding to.

로 나타내기로 한다.The pose of the parking vehicle (hereinafter referred to as the parking vehicle pose) is the center of the rear wheel axis (CRA) as the parking space coordinate system.

It will be represented by.

로 나타내기로 하며, 차량좌표계상의 장애물의 포즈는

로 나타내기로 한다. Also, the parking space pose in the vehicle coordinate system

And the pose of the obstacle in the vehicle coordinate system is

It will be represented by.

로 나타낼 수 있다. When a parking space is specified using the image sensor of a parked vehicle, the parking completion point specified in advance for the parking space is used in the vehicle coordinate system.

It can be expressed as

와 같이 정의하면, 주차공간 좌표계상의 주차 차량 포즈는 수학식 1과 같이 검출할 수 있다. For example, the parking space pose in the vehicle coordinate system

If defined as, the parking vehicle pose on the parking space coordinate system can be detected as shown in Equation 1.

는 포즈변환 메트릭스를 나타내며,

는 차량좌표계상의 주차공간 헤딩각을 나타내며,

는 차량좌표계상의 주차 공간 포즈를 나타낸다. here,

Represents the pose transformation matrix,

Represents the parking space heading angle in the vehicle coordinate system,

Represents a parking space pose in the vehicle coordinate system.

That is, as shown in FIG. 2, when a parking space pose in the vehicle coordinate system is detected, the heading angle of the parking space is reflected based on the pose conversion matrix, thereby enabling detection of a parking vehicle pose in the parking space coordinate system.

With reference to FIG. 2, arbitrary positions (points) in the vehicle coordinate system and the parking space coordinate system according to an embodiment of the present invention and the transformation relationship between them must have been sufficiently understood, and a method of estimating a fall pose will be described. .

그 시간 미분을

라 할 때 상태 변수는

로 나타내기로 한다. The speed-acceleration modeling of the parked vehicle using the vehicle state variable may be expressed as Equation 2 below. Here, the speed of the vehicle

That time derivative

When d, the state variable is

It will be represented by.

는 시간 상수(time constant)이며,

,

,

는 차량에 가해지는 가속도 명령이다.here,

Is a time constant,

,

,

Is the acceleration command applied to the vehicle.

If Equation 2 is expressed as a discrete model equation, it can be expressed as Equation 3.

에 대하여

와

로 각각

와

의 이산화 모델이다. Give here

about

Wow

Each with

Wow

Is the discretization model.

로 표시할 때, 종횡 모션 모델링은 수학식 4와 같이 나타낼 수 있다. 여기서, 주차 차량 포즈는 주차 공간에 대해 주차 완료시 주차 차량의 후륜축 중심(CRA: Center of Rear Axle)이 위치하는 주차 완료점의 포즈로 나타낼 수 있다. Parked vehicle pose

When expressed as, vertical and horizontal motion modeling can be expressed as in Equation 4. Here, the parked vehicle pose may be expressed as a pose of a parking completion point where the center of the rear wheel axis (CRA) of the parked vehicle is located when parking is completed in the parking space.

는 차량의 속도,

는 휠베이스,

이다.here

Is the vehicle's speed,

The wheelbase,

to be.

에 대하여 수학식 4를 오일러 방식(Forward-Euler) 으로 이산화 모델식으로 나타내면, 수학식 5와 같이 나타낼 수 있다. Cycle

If Equation 4 is expressed as a discrete model equation in the Forward-Euler method, it can be expressed as Equation 5.

이다. 차량 속도 제어값인 가속도 명령(

)을 이용하여 주차 차량의 속도 예측치(

)가 계산되며, 주차 차량의 속도 예측치(

)가 계산됨에 따라 수학식 4의

및

가 갱신될 수 있다. here,

to be. Acceleration command, which is the vehicle speed control value (

) To predict the speed of the parked vehicle (

) Is calculated, and the predicted speed of the parked vehicle (

) Of Equation 4 as calculated

And

Can be updated.

Here, the speed predicted value may be calculated by Equation 6.

는 차량 속도 측정치(

)를 이용하여 계산될 수 있다. here,

Is the vehicle speed measurement (

) Can be used.

This can be expressed as Equation 7.

는 수정 게인을 나타낸다. 수학식에서 각각의 변수에 대한 정의 부탁드리겠습니다. here,

Represents the correction gain. Please define each variable in the equation.

In step 120, the pose estimating apparatus 100 estimates a parking space pose in the vehicle coordinate system using the parking vehicle pose in the parking space coordinate system estimated based on the pose transformation matrix.

The relationship between the vehicle coordinate system and the parking space coordinate system's pose transformation is the same as described in Equation 1, so a duplicate description will be omitted.

The pose estimating apparatus 100 may perform estimation transformation of the parking space pose on the vehicle coordinate system by using the parking vehicle pose on the parking space coordinate system estimated using Equation 8 below.

In summary, the pose estimation apparatus 100 according to an embodiment of the present invention estimates the vehicle pose in the parking space coordinate system using at least one of the vehicle speed and steering information, and then calculates the pose in the vehicle coordinate system based on the pose transformation matrix. You can estimate the parking space pose.

In this way, when the parking space pose is estimated, a parking path is generated using the estimated vehicle pose and the parking space pose, and then steering control of the vehicle is possible to follow the parking path. Accordingly, the vehicle can control the steering of the vehicle to follow the corresponding parking path to enable autonomous parking.

)까지의 주차 경로를 생성한 후 경로를 주차차량이 추종하도록 제어하면서 주차차량이 주차 경로를 따라 주차를 진행함에 있어 갱신되는 주차차량의 포즈에 따라 주차경로를 갱신함으로써 자율로 주차 제어할 수 있다.The pose of the parking vehicle at a specific point in the parking space (

), it is possible to control the parking autonomously by updating the parking route according to the updated pose of the parked vehicle when the parked vehicle proceeds to park along the parking route while controlling the route to follow the parked vehicle after creating the parking route to ). .

3 is a block diagram schematically showing an internal configuration of a pose estimation apparatus for estimating a parking space pose linked to a vehicle according to an embodiment of the present invention.

The pose estimation apparatus 100 may be interlocked with an electronic control unit (ECU) of a vehicle or may be provided as a component of an electronic control unit. That is, the pose estimation apparatus 100 may use sensor values of various sensors mounted on the vehicle by being interlocked with the electronic control device of the vehicle or provided in one configuration. Hereinafter, even if there is no separate description, the pose estimation device 100 is interlocked with the electronic control device of the amount of the vehicle or provided in one configuration, so that a control signal to use sensor values of various sensors mounted on the vehicle or to control a configuration of the vehicle It should be understood as conveying.

Referring to FIG. 3, a pose estimation apparatus 100 according to an embodiment of the present invention includes an acquisition unit 310, a vehicle pose estimation unit 315, a parking space pose estimation unit 320, a memory 325, and a processor. Consists of 330.

The acquisition unit 310 is a means for acquiring at least one of vehicle speed and steering information from the vehicle every fixed operation period Tc.

The vehicle pose estimation unit 315 is a means for estimating a vehicle pose in a parking space coordinate system according to a vehicle motion using at least one of vehicle speed and steering information. For example, the vehicle pose estimating unit 315 may estimate a vehicle pose on a parking space coordinate system using Equation (5).

This is the same as that described in FIG. 1, and thus a duplicate description will be omitted.

The parking space pose estimation unit 320 estimates a parking space pose in the vehicle coordinate system using the estimated vehicle pose based on the pose transformation matrix. For example, the parking space pose estimating unit 320 may estimate a parking space pose on the vehicle coordinate system using Equation 7. This is the same as that already described in FIG. 1, so a duplicate description will be omitted.

The pose estimating apparatus 100 may estimate a vehicle pose in a parking space coordinate system using at least one of vehicle speed and steering information, and then estimate a parking space pose in the vehicle coordinate system based on the pose transformation matrix.

The memory 325 is a means for storing various instructions (program codes) necessary for performing a method of estimating a vehicle pose, various data derived from this process, and the like.

The processor 330 includes internal components of the pose estimating apparatus 100 according to an embodiment of the present invention (for example, the acquisition unit 310, the vehicle pose estimating unit 315, and the parking space pose estimating unit 320). ), the memory 325, etc.).

According to an embodiment of the present invention, the vehicle may further include a driving control unit (not shown) capable of autonomous parking control using the predicted vehicle pose and the parking space pose. Although not separately described in FIG. 3, the driving control unit may be interlocked with one component of the vehicle together with the pose estimation device or may be included as a component of the vehicle. Accordingly, the driving control unit may generate a route using the predicted vehicle pose and a parking space pose, and control the steering of the vehicle to follow the corresponding route, thereby enabling autonomous parking control.

The apparatus and method according to an embodiment of the present invention may be implemented in the form of program instructions that can be executed through various computer means and recorded in a computer-readable medium. The computer-readable medium may include program instructions, data files, data structures, and the like alone or in combination. Program instructions recorded on a computer-readable medium may be specially designed and configured for the present invention, or may be known to and usable by those skilled in the computer software field. Examples of computer-readable recording media include magnetic media such as hard disks, floppy disks, and magnetic tapes, optical media such as CD-ROMs and DVDs, and magnetic media such as floptical disks. -Includes hardware devices specially configured to store and execute program instructions such as magneto-optical media and ROM, RAM, flash memory, and the like. Examples of the program instructions include not only machine language codes such as those produced by a compiler, but also high-level language codes that can be executed by a computer using an interpreter or the like.

The above-described hardware device may be configured to operate as one or more software modules to perform the operation of the present invention, and vice versa.

So far, the present invention has been looked at around the embodiments. Those of ordinary skill in the art to which the present invention pertains will be able to understand that the present invention can be implemented in a modified form without departing from the essential characteristics of the present invention. Therefore, the disclosed embodiments should be considered from an illustrative point of view rather than a limiting point of view. The scope of the present invention is shown in the claims rather than the foregoing description, and all differences within the scope equivalent thereto should be construed as being included in the present invention.

100: pose estimation device
310: acquisition
315: vehicle pose estimation unit
320: parking space pose estimation unit
325: memory
330: processor

Claims (9)

In the parking space pose estimation method,
(a) acquiring at least one of vehicle speed and steering information;
(b) estimating a vehicle pose in a parking space coordinate system according to a vehicle motion using at least one of the vehicle speed and steering information; And
(c) estimating a parking space pose in a vehicle coordinate system using the estimated vehicle pose based on a pose transformation matrix.
The method of claim 1,
The step (b),
Parking space pose estimation method, characterized in that the vehicle pose in the parking space coordinate system during parking using the steering information is predicted by the following equation.

here,

Represents the current vehicle pose in the parking space coordinate system,

Indicates steering information,

,

Is,

Is

Indicates a prediction for
The method of claim 1,
The step (b),
Parking space pose estimation method, characterized in that the vehicle pose in the parking space coordinate system during parking using the steering information is predicted by the following equation.

here,

Represents the current vehicle pose in the parking space coordinate system,

Indicates steering information,

,

Is,

Is

Indicates a prediction for
The method of claim 1,
The parking space pose is a pose for a parking completion point, which is a center of a rear wheel axis of a parking vehicle, when parking is completed for the parking space.
A recording medium product on which a program code for performing the method according to any one of claims 1 to 4 is recorded.
In a pose estimation device for estimating a parking space pose in connection with a vehicle,
An acquisition unit that acquires at least one of vehicle speed and steering information;
A vehicle pose estimating unit for estimating a vehicle pose on a parking space coordinate system according to a vehicle motion using at least one of the vehicle speed and steering information; And
A pose estimation apparatus comprising a parking space pose estimating unit for estimating a parking space pose in a vehicle coordinate system using the estimated vehicle pose based on a pose transformation matrix.
The method of claim 6,
The vehicle pose estimation unit,
The vehicle pose on the parking space coordinate system during parking using the steering information is predicted by the following equation,

here,

Represents the current vehicle pose in the parking space coordinate system,

Indicates steering information.
The method of claim 6,
The parking space pose estimation unit,
According to the following equation, the vehicle pose in the parking space coordinate system estimates the parking space pose in the vehicle coordinate system,

here,

Represents the pose transformation matrix,

Represents the steering degree in the parking space coordinate system,

Represents the predicted vehicle pose in the parking space coordinate system.
A sensor for sensing at least one of vehicle speed and steering information; And
Estimating a vehicle pose in a parking space coordinate system according to vehicle motion using at least one of the vehicle speed and steering information, and estimating a parking space pose in the vehicle coordinate system using the estimated vehicle pose based on a pose transformation matrix A vehicle including a pose estimation unit.

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